32 THE EXPERIMENTAL INDUCTION OF DEPENDENT NUTRITION. 



April 25, 1908. A second bud awakening". 



July 6, 1908. All preparations which had been made up to this time 

 were fully exposed to the sun and wind and were drying out. This pro- 

 ceeded at such a rate that all were dead when examined on October 9, 1908. 



December 1, 1908. A number of regenerated cuttings, one of an etio- 

 lated and greened shoot, were inserted in the body of an Echinocactus in 

 the glass-house. 



March 9, 1909. Some of the insertions of Cissus had developed 2 or 3 

 leaves, but were beginning to flag under the influence of the temperature, 

 which reached 110 or even 112 F. in the middle of the day. 



March 30, 1909. Insertions of slips of Cissus laciniata which had nar- 

 rower leaf-divisions were in good condition, while those of the broader 

 leaved C. digitata were dropping off. Some shade for the preparations was 

 arranged. 



April 5, 1909. Several slips had been inserted in the basal portion of 

 an upturned plant early in March, and one displayed an active bud. 



May 7 , 1909. The slip on the upturned plant noted above was growing 

 vigorously, and displayed a series of leaves in all stages of development. 

 Three slips on a large plant in shade active and two quiescent. One had 

 formed a long aerial root. 



June 12, 1909. The slip on the upturned plant which had been put in 

 a shaded room was growing vigorously; others were active, and one was 

 dying. The tip of the longest aerial root was directed into a puncture 

 made in the host. 



July 30, 1909. Plants in same general condition, but long stem of Cis- 

 sus in the laboratory had been broken, probably as a result of injury by 

 a rodent. 



OcfoberS, 1909, Seven arrangements alive, all in shaded rooms and 

 with consequent small leaf -development. Three plants had sent out aerial 

 roots, which, entering the sinuses of the body of the bisnaga, had become 

 fastened, although it was not yet known whether penetration had been 

 affected or not. 



November 8, 1909. Surviving insertions of Cissus on Echinocactus were 

 dissected and no root-formation was detected. Nearly all of the devel- 

 opment exhibited had been at the expense of the balance of water and 

 material in the slip at the time of its insertion, although some absorption 

 may have taken place through dead but moist tissues. 



The water-balance in the echinocacti undergoes great fluctuations, and 

 a series of analyses of material taken at the height of the wet and dry 

 seasons was planned. In addition an analysis was made of a plant that 

 had been brought into the laboratory in November, 1908, and kept with- 

 out a supply of am kind until July 17, 1909, during which time it lost 

 about 35 per cent of its total weight and perhaps over 40 per cent of its total 

 amount of water. It was then found that the sap from the pulp had an 

 acidity equivalent to 0.1064 gram of H,SO, per 100 c.c. The total solids 

 were 7.060 grams per 100 c.c, of which 3 grams was inorganic mate- 

 rial or ash. From this it may be readily seen that absorption from the 

 body of an Echinocactus in this stage by a stem of Cissus would be impos- 

 sible, unless the Cissus had undergone similar concentration. 



